UC San Diego

Background & aims

Vibration-controlled transient elastography (VCTE), which measures liver stiffness, has become an important tool for evaluating patients with nonalcoholic fatty liver disease (NAFLD). We aimed to determine the diagnostic accuracy of VCTE in detection of NAFLD in a multicenter cohort of patients.

Methods

We performed a prospective study of 393 adults with NAFLD who underwent VCTE within 1 year of liver histology analysis (median time, 49 d; interquartile range, 25-78 d), from July 1, 2014, through July 31, 2017. Liver stiffness measurement (LSM) cut-off values for pairwise fibrosis stage and controlled attenuation parameter cut-off values for pairwise steatosis grade were determined using cross-validated area under the receiver operating characteristics curve (AUROC) analyses. Diagnostic statistics were computed at a sensitivity fixed at 90% and a specificity fixed at 90%.

Results

LSM identified patients with advanced fibrosis with an AUROC of 0.83 (95% CI, 0.79- 0.87) and patients with cirrhosis with an AUROC of 0.93 (95% CI, 0.90-0.97). At a fixed sensitivity, a cut-off LSM of 6.5 kPa excluded advanced fibrosis with a negative predictive value of 0.91, and a cut-off LSM of 12.1 kPa excluded cirrhosis with a negative predictive value of 0.99. At a fixed specificity, LSM identified patients with advanced fibrosis with a positive predictive value of 0.71 and patients with cirrhosis with a positive predictive value of 0.41. Controlled attenuation parameter analysis detected steatosis with an AUROC of 0.76 (95% CI, 0.64-0.87). In contrast, the VCTE was less accurate in distinguishing lower fibrosis stages, higher steatosis grades, or the presence of NASH.

Conclusions

In a prospective study of adults with NAFLD, we found VCTE to accurately distinguish advanced vs earlier stages of fibrosis, using liver histology as the reference standard.